To factory reset a Genius Valve:
- Remove the battery cover and one battery.
- Press and hold down the middle ('o') button.
- Re-insert the battery whilst still holding the middle button.
- The valve will perform a screen test and show all the icons.
- Keep the button pressed until the screen goes blank.
- Release the middle button.
- If successful the valve will go into mount mode and 'M' will flash on the screen.
